This article makes a lot of good points; but it is also misleading, because it conflates “ open-sea mariculture” with “geoengineering”.
The Haida wanted more salmon, and they succeeded. That’s the open-sea mariculture part, and so far it’s been a good thing.
OTOH, Russ George (and others of his ilk) are interested in geoengineering — so that they can make a bundle, selling carbon-offset credits. George tried this years ago, and got shut down.
While it would be great to rid ourselves of carbon rationing, by the simple expedient of dumping iron filings into the ocean — there’s a large risk of going too far. Several year ago, oceanographer John Martin said: “Give me half a tanker of iron and I’ll give you the next ice age.” The intent of geoengineering with iron filings would be to get rid of only the “surplus” carbon dioxide. Of course, the problem is determining how much CO2 is surplus (if any).
This is a lot riskier than the article makes out.
You’re right about doing this geoengineering with iron sulfate willy nilly. It could be too soon to see any bad results from it.